PMID- 20174762
OWN - NLM
STAT- MEDLINE
DCOM- 20101005
LR  - 20101007
IS  - 2567-689X (Electronic)
IS  - 0340-6245 (Linking)
VI  - 103
IP  - 5
DP  - 2010 May
TI  - Age is a determinant factor for measures of concentration and effect in children 
      requiring unfractionated heparin.
PG  - 1085-90
LID - 10.1160/TH09-09-0624 [doi]
AB  - Previous studies investigating continuous unfractionated heparin (UFH) therapy 
      report age-related differences in UFH response in children, as measured by APTT 
      and anti-Xa assay. This study determined the age-related response following 
      administration of a single UFH bolus of 75-100 IU/kg in children. Venous blood 
      samples were collected from children (n=56) at 15, 30, 45 and 120 minutes 
      post-UFH. Anti-Xa, anti-IIa, APTT, TCT and protamine titration were performed on 
      all samples. Age-dependent differences in the effect and concentration of UFH 
      were identified for the anti-Xa, anti-IIa and protamine titration assays, 
      respectively. In addition, a trend suggesting a proportional increase in anti-Xa 
      and anti-IIa-mediated UFH effect with age was evident. Logistic regression 
      demonstrated an increase in protamine titration of 0.6 IU/ml for every year of 
      age in samples collected 15 minutes post-UFH. UFH-mediated anti-IIa activity was 
      reduced compared to anti-Xa activity across childhood, with a two-fold increase 
      in anti-Xa to anti-IIa ratio in infants less than one year of age compared to 
      teenagers in the setting of high UFH concentrations. This study demonstrates that 
      the previously reported age-dependent response to UFH occurs in the context of an 
      age-dependent serum concentration of UFH. The trend toward increased UFH serum 
      concentration and anticoagulant activity with age may be related to short-term 
      differences in UFH binding to coagulant and competitive plasma proteins in vivo.
FAU - Newall, Fiona
AU  - Newall F
AD  - Department of Paediatrics, The University of Melbourne, Melbourne, Australia. 
      fiona.newall@rch.org.au
FAU - Ignjatovic, Vera
AU  - Ignjatovic V
FAU - Johnston, Linda
AU  - Johnston L
FAU - Summerhayes, Robyn
AU  - Summerhayes R
FAU - Lane, Geoff
AU  - Lane G
FAU - Cranswick, Noel
AU  - Cranswick N
FAU - Monagle, Paul
AU  - Monagle P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100219
PL  - Germany
TA  - Thromb Haemost
JT  - Thrombosis and haemostasis
JID - 7608063
RN  - 9005-49-6 (Heparin)
RN  - EC 3.4.21.6 (Factor Xa)
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - *Age Factors
MH  - Child
MH  - Child, Preschool
MH  - *Drug Dosage Calculations
MH  - Evidence-Based Medicine
MH  - Factor Xa/metabolism
MH  - Female
MH  - Heparin/analogs & derivatives/blood/*therapeutic use
MH  - Humans
MH  - Infant
MH  - Infant, Newborn
MH  - Male
MH  - Partial Thromboplastin Time/methods
MH  - Practice Guidelines as Topic
MH  - Reference Values
EDAT- 2010/02/23 06:00
MHDA- 2010/10/06 06:00
CRDT- 2010/02/23 06:00
PHST- 2009/09/06 00:00 [received]
PHST- 2010/01/05 00:00 [accepted]
PHST- 2010/02/23 06:00 [entrez]
PHST- 2010/02/23 06:00 [pubmed]
PHST- 2010/10/06 06:00 [medline]
AID - 09-09-0624 [pii]
AID - 10.1160/TH09-09-0624 [doi]
PST - ppublish
SO  - Thromb Haemost. 2010 May;103(5):1085-90. doi: 10.1160/TH09-09-0624. Epub 2010 Feb 
      19.